He says this approach dramatically simplifies and speeds up manufacturing, making it as easy as "buttering toast."

They make 10-meter-long battery sheets which are stacked on top of each other to increase capacity. These resin-based batteries are also resistant to catching fire when punctured.

In March, APB raised $74 million. This will be used to build a plant in central Japan with 1 gigawatt-hour capacity by 2023.

APB will first focus on stationary batteries used in buildings, offices and power plants. The stationary battery market will be worth $100 billion by 2025 worldwide — more than five times its size last year — according to estimates by Wood Mackenzie.

APB has already lined up its first customer, a large Japanese company whose niche and high-value-added products sell mostly oversea

Nissan is also working on all polymer batteries. Nissan licensed the technology to APB in 2018.